Strange Noise, Driveshaft?

LOL, not drinking...

No psychedelic mushrooms either, lol!!!

It only makes the noise one time when I slow down, then it doesn't do it until I speed up to about 10-12 mph, then slow down again, very strange. It is either the pop, or the ding, or the boing noise. Like when you have a 3/8" tall by about 1/8" wide tab of sheet metal and you flick it, kind of noise, like doe-ing. I know I am crazy, but I'm not hallucinating, I captured the noise on my phone and took it to an expert who was stumped. I plan on swapping out the drive shaft anyway, because it is stock and I need a much stronger one. It will handle 700-800 hp, the new one. If it still makes the noise, I have no idea what to do, no one seems to know.

Thanks.